# US 11,028,697 B2 · Low speed fan for gas turbine engines

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- Number: US 11,028,697 B2
- Document ID: US11028697B2
- Status: Granted
- Kind: B2
- Application number: 14/761,348
- Filed: 2013-12-19
- Published: 2015-12-24
- Granted: 2021-06-08
- Earliest claimed: 2013-03-14
- Assignees: Raytheon Technologies Corporation
- Applicants: United Technologies Corporation
- Inventors: Gary D. Roberge
- Web page: https://patentgrep.com/patent/US11028697B2

## CPC

- F01D 5/02: Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28})
- F01D 5/147: {Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18)}
- F01D 5/225: {by shrouding}
- F01D 5/282: {Selecting composite materials, e.g. blades with reinforcing filaments}
- F01D 5/3061: {by welding, brazing}
- F01D 5/3069: {between two discs or rings}
- F01D 5/34: Rotor-blade aggregates of unitary construction {, e.g. formed of sheet laminae; (discs formed of sheet laminae F01D5/028; ceramic materials F01D5/284, composite materials F01D5/282)}
- F02C 3/04: having a turbine driving a compressor (power transmission arrangements F02C7/36; control of working fluid flow F02C9/16)
- F02K 3/06: with front fan
- F04D 29/023: {especially adapted for elastic fluid pumps}
- F04D 29/321: {for axial flow compressors}
- F04D 29/324: {Blades}
- F04D 29/325: {for axial flow fans (blade mountings F04D29/34, blades F04D29/38)}
- F04D 29/34: Blade mountings {(for axial flow compressors F04D29/322)}
- F05D 2220/32: in gas turbines
- F05D 2220/36: specially adapted for the fan of turbofan engines
- F05D 2230/23: by permanently joining parts together
- F05D 2230/232: by welding
- F05D 2230/234: Laser welding
- F05D 2230/60: Assembly methods
- F05D 2300/121: Aluminium
- F05D 2300/133: Titanium
- F05D 2300/43: Synthetic polymers, e.g. plastics; Rubber
- F05D 2300/603: Composites; e.g. fibre-reinforced
- Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft
- Y10T 29/49323: Assembling fluid flow directing devices, e.g., stators, diaphragms, nozzles
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00)
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A fan section for a gas turbine engine is disclosed herein. The fan may include a rotor disk and a plurality of airfoils fixedly attached to and supported by the rotor disk as a single unitary piece. The airfoils may extend radially outward from the rotor disk with respect to an engine axis. The rotor disk may be made of metal and the airfoils may each be made at least partially of an organic matrix composite.

## Claims

### Claim 1

A fan section for a gas turbine engine, comprising:
a rotor disk made of metal; and
a plurality of airfoils fixedly attached to and supported by the rotor disk as a single unitary piece and extending radially outward from the rotor disk with respect to an engine axis, each airfoil having a collar bonded to a radially outermost surface of the rotor disk, the collar having an outer surface that is flush with an exterior surface of the airfoil, wherein each collar fixedly secures a respective one of the plurality of airfoils to the rotor disk, and each of the plurality of airfoils being made at least partially of an organic matrix composite, and wherein each collar is positioned around a respective base of a respective one of the plurality of airfoils and extends radially above the radially outermost surface of the rotor disk.

### Claim 2 (depends on 1)

The fan section of claim 1, wherein the collar is made of one of aluminum and titanium.

### Claim 3 (depends on 1)

The fan section of claim 1, further comprising a plurality of shear lugs, each of the plurality of shear lugs extending through one of the plurality of collars and one of the plurality of airfoils.

### Claim 4 (depends on 1)

The fan section of claim 1, wherein the airfoil includes a body and an edge extending radially along the body, the body being formed from the organic matrix composite and the edge being formed of a metallic material.

### Claim 5 (depends on 1)

The fan section of claim 1, wherein the airfoils include a body and an edge extending radially along the body, the body being formed from a first metallic material and the edge being formed from a second metallic material.

### Claim 6 (depends on 1)

The fan section of claim 1, further comprising a tip shroud connecting adjacent airfoils at a tip of each airfoil.

### Claim 7 (depends on 1)

The fan section of claim 1, wherein the airfoils further include a side panel formed along a body of the airfoil, the side panel being formed from an organic matrix composite.

### Claim 8 (depends on 1)

The fan section of claim 1, further comprising a partial-span shroud connecting adjacent airfoils, the partial-span shroud extending from a point on each airfoil located between a base and a tip of each airfoil to a similar point on adjacent airfoils.

### Claim 9 (depends on 8)

The fan section of claim 8, wherein the partial-span shroud is cast, fixedly attached, or fabricated as one unitary piece with the airfoils.

### Claim 10 (depends on 6)

The fan section of claim 6, wherein the tip shroud is one of cast, fixedly attached, and fabricated as one unitary piece with the airfoils.

### Claim 11 (depends on 6)

The fan section of claim 6, further comprising an outer-span blade attached to at least one of the tip of the airfoil and the tip shroud, wherein the outer-span blade is one of cast, fixedly attached, and fabricated as one unitary piece with the airfoils.

### Claim 12 (depends on 1)

The fan section of claim 1, wherein each airfoil has a tip, and the tips of the airfoils rotate at a maximum speed of 1050 feet per second or less.

### Claim 13

A gas turbine engine, comprising:
a fan section having a rotor disk made of metal, and a plurality of airfoils, the airfoils being fixedly attached to and supported by the rotor disk as a single unitary piece and extending radially outward from the rotor disk with respect to an engine axis, each airfoil of the plurality of airfoils having a collar bonded to a radially outermost surface of the rotor disk, the collar having an outer surface that is flush with an exterior surface of the airfoil, wherein each collar fixedly secures a respective one of the plurality of airfoils to the rotor disk, each of the plurality of airfoils being made at least partially of an organic matrix composite, and wherein each collar is positioned around a respective base of a respective one of the plurality of airfoils and extends radially above the radially outermost surface of the rotor disk;
a compressor section downstream from the fan section;
a combustor downstream from the compressor section; and
a turbine section downstream from the combustor and in mechanical communication with the fan section and compressor section via an engine shaft.

### Claim 14 (depends on 13)

The gas turbine engine of claim 13, wherein each airfoil includes a body, an edge and a side panel, each body, edge and side panel being made of one of organic matrix composite and metal.

### Claim 15

A method of forming a fan section of a gas turbine engine, the method comprising:
providing a rotor disk made of metal; and
fixedly attaching a plurality of airfoils to the rotor disk with a plurality of collars, each airfoil being made at least partially of organic composite matrix and each collar being bonded to a radially outermost surface of the rotor disk and each collar having an outer surface that is flush with an exterior surface of the airfoil, wherein each collar is positioned around a respective base of a respective one of the plurality of airfoils and extends radially above the radially outermost surface of the rotor disk.

### Claim 16 (depends on 15)

The method of claim 15, further comprising fixedly attaching a partial-span shroud to adjacent airfoils.

### Claim 17 (depends on 15)

The method of claim 15, further comprising fixedly attaching a tip shroud between adjacent airfoils.

### Claim 18 (depends on 17)

The method of claim 17, further comprising fixedly attaching an outer-span blade to at least one of the airfoil and the tip shroud as a tip-biased aerodynamic extension of the rotor airfoils.